Apparatus for metering and dispensing liquid mixtures



Aug. 4, 1959 A. F. M. BLANCHET ET AL 2,893,002

APPARATUS FOR METERING AND DISPENSING LIQUID MIXTURES Filed March 6,1957 2 Sheets-Sheet 1 FIG. I

INVENTORS E M.BLANCHET A.M.J. MEYER ATTORNEYS Aug. 4, 1959 A. F. M.BLANCHET ET AL 2,898,002

APPARATUS FOR METERING AND DISPENSING LIQUID MIXTURES Filed March 6,1957 2 Sheets-Sheet 2 2 FIG. 2

INVENTORS ANDRE E M.BLANCHET JEAN G. A. MJ. MEYER ATTO R N EYS UnitedStates Patent APPARATUS FOR METERING AND DISPENSING LIQUID MIXTURESAndre Francois M. Blanchet, Saint-Denis, and Jean Gustave A. M. J.Meyer, Neuilly-sur-Seine, France, assignors to SATAM-Societe Anonymepour Tons Appareillages Mecaniques, Paris, France Application March 6,1957, Serial No. 644,352 t Claims priority, application France March 9,'1956 13 Claims. (Cl. 222-26) The present invention relates to apparatusfor dispensing liquids, and more particularly to an improved system andmechanism for metering and dispensing mixtures of liquids. While theinvention is applicable, in principle, to the metering and dispensing ofmixtures of any liquids, it is presently contemplated that the apparatusof the invention will be employed in connection with the dis pensing ofmixtures of gasoline and oil, or of different grades of gasoline. In thefollowing description, therefore, specific reference will be made to anapparatus for mixing and dispensing gasoline-oil mixtures, suchapparatus being illustrative of the invention.

As one of its primary features, the present invention provides animproved apparatus for metering and dispensing a mixture of liquids,which may be readily adjusted to accommodate a variety of mixtureratios, and which .includes means operative to indicate the total priceof the mixture dispensed, regardless of the ratio of liquid comprisingthe mixture. More specifically, the apparatus includes selectivelyoperable means for varying the ratio of liquids in the mixturedispensed, the selectively operable means being further adaptedautomatically to condition a price indicating device to act in responseto the unit price of the selected mixture. In one of its advantageousforms, the new apparatus includes normally fixed, but readily adjustablemeans for setting the unit prices of the various contemplated mixtures,to accommodate periodical changes in the selling prices of the variouscomponent liquids of the mixture.

One of the more specific advantageous features of the invention residesin the provision, in combination with a dispensing system for a mixtureof a plurality of liquids, of a novel and improved metering andregistering system whereby the relative proportions of the respectivecomponent liquids. may be varied with ease and precision, and the totalprice and volume of the mixture dispensed is automatically registered,at any selected ratio of component liquids. In this respect, theapparatus of the invention accounts for variations in unit price betweenthe various component liquids, compensation for such variations beingmade automatically, upon setting of the apparatus for delivery of aselected mixture. Advantageously, the new apparatus is so arranged thatthe ratio of component liquids in the mixture may be varied one or moretimes during the dispensing of a predetermined volume of liquid mixture,to obtain various intermediate mixture ratios, and at the same time givea precise indication of the selling price of the intermediate mixturedelivered.

Another specific feature of the invention resides in the provision of asystem for dispensing an accurately metered mixture of liquids, such asgasoline and oil, in which means are provided for operating separatemetering devices for the liquids at predetermined, accurately relatedspeeds, without placing excessive operating loads upon any of themeters. In this respect, it is desirable to drive one of the meteringdevices, such as ice the oil meter, by means of a mechanicalinterconnection with the other metering device, such as the gasolinemeter, the force imparted by the flow of gasoline through its meterbeing sufiicient to drive the oil meter through the mechanicalinterconnection. In dispensing a viscous liquid such as oil, however,diificulties are often encountered in connection with the placing ofexcessive load upon the driving metering device. Moreover, the magnitudeof the load may vary widely as the viscosity of the oil changes fromtime to time, due to temperature variations or other causes.Accordingly, in the apparatus of the invention, a dispensing system isprovided for the oil, in which oil in the system, upstream of the oilmeter, is under considerable pressure, but not to such an extent as tocause the oil meter to be operated independently of actuation of thegasoline meter. The arrangement is such, however, that upon actuation ofthe gasoline meter in the usual manner, the oil meter is brought intooperation with a minimum of load upon the gasoline meter.

An ancillary feature of the invention resides in the provision, in asystem for metering and dispensing a mixture of liquids, such asgasoline and oil, of improved means automatically preventing thedelivery of one component liquid when the supply of the other isexhausted, or when, for some reason, the flow thereof is interrupted.

Further advantageous [features of the invention will become apparentupon consideration of the following detailed description of a preferredembodiment of the invention, taken in connection with the accompanyingdrawings, in which:

Fig. 1 is a simplified schematic representation of a system for meteringand dispensing a mixture of gasoline and oil, the system incorporatingthe several improved features of the invention;

*Fig. 2 is an enlarged cross sectional view of a com- :bined mixtureratio changing and price registering mechanism incorporated in thesystem of Fig. 1, and

Fig. 3 is an enlarged fragmentary view of a gear mechanism forming apart of the mechanism of Fig. 2.

Referring now to the drawing, and initially to Fig. 1 thereof, thenumerals 10, lldesignate, respectively, storage tanks for componentliquids of a mixture. In the illustrated system, the tank 10 is intendedto contain a supply of gasoline, while the tank 11 is intended tocontain a supply of oil.

A conduit 12 extends into the gasoline supply tank 10 and is connected,through a suitable filter 13, to the intake of a pump 14 drivenalternatively by means of a motor 15 or manually operated crank 16. Aconduit 17 is connected to the outlet of the pump 14 and extends into aseparator 18. The separator 18 may be of ordinary construction, and isadapted to separate vapors and gases from the liquid gasoline.

Gases and vapors are periodically let off from the separator 18, byoperation of a float valve 19, and passed through a conduit 20 into apurge tank 21. The purge tank 21 has a gas outlet 22, exhausting to theatmosphere, and a float valve-controlled outlet 23 adapted periodicallyto discharge collected liquid gasoline into a conduit 24, to be returnedto the supply tank 10.

At or adjacent the bottom of the separator 18 is an outlet 25, fromwhich liquid gasoline is discharged into a conduit 26 leading, through acheck valve 27, to the inlet of a liquid flow meter 28, advantageouslyof the positive displacement type. The outlet of the meter 28 isconnected to a conduit 29 leading to a dispensing nozzle 30. The nozzle30 has a valve 31, which is normally held in a closed position, as bythe action of a spring 32, but which may be opened at desired times byoperation of a lever 33.

When the pump 14 is in operation, gasoline may be dispensed from thenozzle 30 by appropriate pperation 3 of the lever 33. When thelever-actuated valve 31 is closed, and the pump 14 is in operation,gasoline flows from the downstream or outlet side of the pump to theupstream or inlet side thereof through a by-pass system includingconduits 34, 35 and a spring-loaded, normally closed relief valve 36.

In the illustrated form of the invention, the oil storage tank 11 has afloat valve-controlled outlet 37 discharging into a conduit 38 whichleads, through a suitable filter 39, to the inlet of a pump 40mechanically connected to the gasoline pump 14 and adapted to be driventherewith, by means of the motor or crank 16. The outlet of the oil pump40 is connected to a conduit 41 leading to the inlet of a liquidmetering device 42, to be further described, which is advantageously ofthe positive displacement type. A conduit 43 is connected to the outletof the oil meter 42 and leads to the dispensing nozzle 30. The nozzle 30has a spring-operated, normally closed valve 44, which is forced open byoil under pressure whereby the oil may be discharged into and from thenozzle.

In the system of the invention, the oil meter 42 is mechanicallyinterconnected with the gasoline meter 28, by a mechanism 45 to bedescribed, so that the oil meter is caused or permitted to operate, topass oil, only during times when the gasoline meter 28 is in operation.Accordingly, a by-pass system, including conduit 46 and springloadedrelief valve 47, is provided connecting the upstream and downstreamsides of the oil pump 40, to prevent the buildup of excessive pressurein the system.

In accordance with one aspect of the invention, the downstream or outletside of the oil pump 40 is connected, by means of a conduit 48 to theactuator of a pressure responsive valve 49. The valve 49 is spring urgedto an open position, tending to provide a flow passage through a conduit50 which, together with the conduit 35, forms an auxiliary by-passsystem connecting the upstream and downstream sides of the gasoline pump14. The arrangement is such that, in the absence of a predeterminedfluid pressure in the oil conduit 41, the bypass systems 50, 35 willopen to prevent the flow of gasoline. Accordingly, when the supply ofoil is exhausted, or for some other reason is interrupted, the flow ofgasoline will also be terminated. Further, in this respect, it will beunderstood that the flow of oil is precluded when the supply of gasolineis exhausted or otherwise interrupted, since, as will he discussed inmore detail, the oil meter cannot operate, to pass oil, in the absenceof operation of the gasoline meter.

In accordance with another aspect of the invention, the oil meter 42 isof a positive displacement type and is of a design such that theapplication to the inlet side thereof of a relatively substantial fluidpressure will not cause the meter to operate, against the variousfunctional forces acting upon the meter. To this end, the oil meter 42may be a piston meter, in which the crank arms driven by the pistons areof short length. Similarly, the meter 42 may be 'a gear meter, in whichthe gears and gear-tooth profiles are such that fluid under pressure, atthe inlet of the meter, acts upon the moving parts thereof through a lowmechanical advantage, to an extent such that substantial fluid pressuresat the inlet side of the meter will not operate, independently, to setthe meter in motion.

The provision of an oil meter which does not operate independently evenunder substantial fluid pressures, is advantageous in that the oil maybe maintained under substantial pressure by the pump 40, to the endthat, when the oil meter is set in operation, the oil flows readilythrough the meter. Thus, in accordance with this aspect of theinvention, the viscosity of the oil does not materially effect theoperation of the system, and in addition, changes in oil viscosity, suchas may occur from time to time with changing temperature conditions,etc., has relatively little effect upon the operation of the system.

Referring now to Figs. 2 and 3, there is shown an improved mechanism,for interrelating the operation of the gasoline and oil meters 28, 42and causing the selling price of the delivered mixture to be registered.The mechanism includes a housing 51 upon opposite walls of which therespective meters 28, 42 may be mounted.

Extending into the housing 51, from the gasoline meter 28, is a shaft52, which is adapted to be rotated during operation of the meter andwhich has keyed thereto a plurality of gears 52a52d. By way of example,and not of limitation, the shaft 52 may be arranged to rotate throughone complete revolution in response to the passage through the meter 28of one liter (or gallon) of gasoline, and the gears 52a52d each may beprovided with teeth. Similarly, a shaft 53, adapted for rotation duringoperation of the oil meter 42, extends into the housing 51 and has keyedthereto a plurality of gears 53a53d. By way of example, the shaft 53 maybe arranged to make one complete revolution in response to the passagethrough the meter 42 of one-tenth liter (or gallon) of oil, and thegears 53a--53d each may be provided with 100 teeth.

At the ends of the meter shafts 52, 53 are sets of bevel gears 54, 55which drive indicators 56, 57 respectively, to provide a continuousindication of the total revolutions of the respective shafts and henceof the total volumes of liquid delivered through the respective meters28, 42.

Journaled in the housing 5'1, in parallel relation to the meter shafts52, 53, is an elongated shaft 58, which may be referred to as the mainshaft, and which has a portion 58a projecting out of the housing 51 andinto a second housing or frame 59. Keyed to the main shaft 58 areconical sets of gears 60a-60d and 61a61a', each set comprising fourgears of graduated sizes. By way of example, the gears 60a-60d may have,respectively 96, 97, 98 and 99 teeth, while the gears 61a61d may have,respectively, 40, 30, 20 and 10 teeth.

Adjacent the gears 60a60d and 61a-61d of each set are levers 62a62d and63a63d, each carrying an idler pinion, as indicated at 64, 65, at oneend. The respective levers 62a62d and 63a63d are mounted for individualpivotal movement with respect to the main shaft 58, whereby therespective idler pinions carried thereby may be selectively brought intoengagement with selected pairs of gears of the sets 52a--52d, 60a60d and53a53d, 61a61d. By way of example, lever 62b may be pivoted to bringpinion 64 into engagement with gears 52b, 6%, while lever 6311 may bepivoted to bring pinion 65 into engagement with gears 53b, 61b,substantially as illustrated in Fig. 2.

For operating the respective levers 62a62d, 63a63d, there is provided acam shaft 66, which is journaled for rotation in the housing 51 andcarries sets of cams 67a67d, 68a68d. The arrangement is such that, uponappropriate rotation of the cam shaft 66, the a cams act upon the alevers to bring the piuions carried thereby into engagement with the agears, etc. Thus, in the illustrated arrangement, the cam shaft 66 is sopositioned that the cams 67b, 68b thereof are acting upon the levers62b, 63b, to position the pinion 64 in engagement with gears 52!), 60band the pinion 65 in engagement with gears 53b, 61b. When the gears areso engaged, rotation of the gasoline meter shaft 52 will effect rotationof the main shaft 58, which, in turn, effects or permits rotation of theoil meter shaft 53.

In the preferred commercial embodiment of the invention, the selectionof gear ratios is such that the main shaft 58 operates through onecomplete revolution during the passage through the meters 28, 42 of acombined volume of one liter (or gallon). Thus the possible drive ratiosbetween the gasoline meter shaft 52, and the main shaft 58 are 96/100,97/100, 98/100 and 99/100, while the corresponding ratios between themain shaft and the oil meter shaft 53 are 40/100, 30/100, 20/100 and10/100. With the apparatus arranged as illustrated in Fig. 2 therespective drive ratios are 97/100 and 30/ 100. Accordingly, upon therotation of the gasoline meter shaft 52 through 97% of a revolution,during the delivery of 97 of a liter (or gallon) of gasoline, the mainshaft is caused to rotate through a complete revolution. This, in turn,causes or permits rotation of the oil meter shaft through 30% of arevolution, eifecting the passage through the oil meter 42 of 3% (.30.l0) of a liter (or gallon) of oil. The total fluid passed through themeters 28, 42 in one revolution of the main shaft 58, is, accordingly,100% of the unit Volume.

By setting the cam shaft 66 in its various operative positions, mixturesof gasoline and oil of various ratios may be obtained. For example, inthe illustrated apparatus, ratios of gasoline to oil may be obtained inthe following ratios 964, 973, 98-2, 99-1. Of course, other mixtures maybe obtained by appropirate selection of gears, and the foregoing shouldbe considered as illustrau've only.

To enable the cam shaft 66 to be adjusted to any of its operativepositions, a gear 69 is carried at one end thereof, in engagement with asecond gear 70 secured to a manually operable shaft 71. The shaft 71,which may be referred to as the adjusting shaft, has a manuallyengageable knob 72 at one end, and extends through suitable hearings inthe housing 51 and frame 59. A pointer or other suitable visualindicator may be carried by the adjusting shaft 71 to facilitateobservation of the adjusted condition thereof at any time. 7

As an important feature of the invention, the main shaft 58 carries, onits projecting portion 58 a conical series 73 of gears of graduateddiameter. The gears of the series 73 are keyed to the shaft 58, forrotation therewith, and are adapted to be placed selectively in drivingengagement with a price indicator 74, in a manner to be described inmore detail. Also keyed to the shaft 58 is a bevel gear 75 which mesheswith a mating gear 76 to drive a volume indicator 77 whereby the totalvolume of mixture delivered through the meter 28, 42, as represented byrotations of the shaft 58, is registered.

Journaled in the frame 59, in parallel relation to the main shaft 58,are shafts 78, 79, arranged in spaced relation about the conical series73 of gears. In the illustrated form of the invention there are foursuch shafts, only two being visible in Fig. 2; and, advantageously, theshafts are spaced uniformly about the conical series of gears. Theshafts 78, 79 are provided with keyways extending throughout asubstantial portion of their length whereby gears 80, slidably supportedthereon, may be maintained in driving engagement with the shaft.

Pivotally and slidably mounted on the shafts 78, 79 are yokes 81, whichcarry, at their outer ends, gears 82. The yokes 81 are generally of Ushape, having their opposite legs disposed on opposite sides of thegears 80 carried by the shafts 78, 79. The gears 80, 82 are arranged forrotation about axes spaced a fixed distance from each other, and are incontinuous driving engagement.

The arrangement is such that the gears 80, 82 and yokes 81 form more orless unitary assemblies, the respective assemblies being rotatable andmovable axially along the shafts 78, 79, each independently of theother.

By moving the gear assemblies 80, 82 axially along the shafts 78, 79,the assemblies may be brought into aligned relation with any of thegraduated gears of the conical series 73 thereof. Thereupon, by pivotingthe yokes 81, the gears 82 may be brought into driving engagement withthe gear of the series with which it is aligned. Accordingly, therespective shafts 78, 79 may be drivingly engaged with the main shaft inany of a variety of driving ratios, by selecting appropriate gears ofthe conical series 73.

In order to manipulate the gear assemblies 80--82 in the mannerdescribed, mechanisms of the type described in French Patent No.842,413, filed February 16, 1939,

3 may be employed. The preferred mechanism comprises threaded shafts 83,journaled at their ends in the frame 59 for rotation about axeseccentric to their geometric axes. The shafts 83 threadedly engage links84, at the outer ends thereof, the iner ends of the links beingpivotally attached to the U-shaped brackets 81 of the gear asemblies-82, advantageously at points coaxial with the gears 82. The shafts 83are disposed along axes parallel to generatrices of the conical envelopeof the gear series 73, as shown in Fig. 2.

Rotation of the shafts. 83, which is accomplished by manual manipulationof knobs 85, causes the links to be oscillated in a transversedirection, as well as advanced longitudinally, one way or the other,along the threaded shafts. Advantageously, the threads of the shafts 83are such that a complete'revolution thereof will cause the links 84, andthe gear assemblies associated therewith, to be advanced longitudinallya distance equal to the spacing between gears of the conical series 73.

During the rotation of one of the shafts 83 the eccentric movement ofthe shaft will cause the link 84 to be moved transversely (see Fig. 3),which, in turn, causes the yoke 81 to be pivoted about the axis of itssupporting shaft 78, to disengage the gear 82 from the adjacent gear ofthe series 73. Rotation of the shaft 83 also moves the link 84, andhence the gear assembly 8082, longitudinally of the supporting shaft 78,and subsequently causes the yoke 81 to be pivoted back to- ;ward theconical gear series 73. The skewed relationship between the threadedshaft 83 and the supporting shaft 78 causes the yoke 81 to assumedifferent angular positions at different longitudinal points along thesupporting shaft 78, and, hence, the gear 82 is brought into meshingengagement with each gear of the series 73 notwithstanding the graduateddiameters of the gears.

It is contemplated that the several gears of the series 73 thereof willbe selected to correspond to the various unit prices of a unit volume ofmixture. Accordingly, as a general rule, each of the four threadedshafts 85 will be adjusted so that the gear assembly associatedtherewith is engaged with a gearof the seies 73 corresponding to theprice of a unit volume of mixture composed of respective componentliquids in the propontions determined by the various operative settingsof the adjusting shaft 71. The different mixtures will, generally, havedifferent unit prices; and, once the appropriate adjustment of thethreaded shafts 83 is made to reflect such price-s, the adjustedsettings are not altered unless and until a change in the price of aunit volume is effected.

As shown in Fig. 2, each of the shafts 78, 79 carries a gear 86 at itsend, and, advantageously, the gears of the respective shafts are offsetaxially from each other. When the system is in operation, the fourshafts 78, 79 rotate simultaneously, each at a speed determined by thegear of the series 73 with which it is engaged.

A gear 87, slidably keyed to a shaft 88, is adapted selectively to bebrought into engagement with any one of the several gears 86, so thatrotation may be imparted to the shaft 88 in accordance with :a selectedunit price. Rotation of the shaft 88 is imparted, by means of bevelgears 89-91 to price indicator 74, which is preferably of a type adaptedperiodically to be reset to zero, and to a totalizer 92 adapted toindicate a cumulative total price of all liquids dispensed from thesystem.

Manipulation of the gear 87, whereby the gear is driving-1y connected toa selected one of the gears 86, is effected by means of a bell cranklever 93, which is pivoted upon a shaft 94 and has one arm engaging agrooved hub 87a provide on the gear 87. The other arm of the crank 93 isdisposed in operative relation to cams 95a-95d carried by the adjustingshaft 71. Accordingly, upon rotation of the shaft 71 to any of itsoperative adjusted positions, to effect a predetermined driving ratiobetween the gasoline and oil meters 28, 42, the bell crank 93 issimultaneously actuated to move the gear 87' into engagement with thatone of the gears 86 which corresponds to the unit price of the selectedmixtures.

Summary of operation As an initial operation, the several threadedshafts are adjusted, by manipulation of knobs 85, until the gearassemblies 80-82 associated therewith are engaged with appropriate gearsof the series 73 corresponding to the respective unit prices of theseveral liquid mixtures which may be dispensed. This adjustment, oncehaving been made, is not altered, except upon a change in the base orunit selling price of the mixtures.

Prior to the initiating of a dispensing operation, the adjusting shaft71 is manipulated, by means of knob 72, to one of its operativepositions, wherein a selected set of a, b, c or d gears is properlyentrained and the respective meters 28, 42 are thereby mechanicallyinterconnected to operate at a predetermined ratio, to deliver a desiredmixture of liquids. Setting of the adjusting shaft 71 simultaneously andautomatically effects the engagement of the gear 87 with the proper oneof the gears 36 to correspond with the unit price of the selectedmixture.

The system is readied for operation by energization of the motor 15 (orcrank 16) to operate the pumps 14, 46, in the gasoline and oil systems,respectively. The pump 14 is, of course, ineffective to create pressurein the gasoline system until a predetermined pressure is established inthe oil system, by reason of the pressure responsive valve 49, whichmaintains by-pass 50, 35 open unless the desired oil pressure is reachedat the outlet or downstream side of the oil pump.

When the pumps 14, 40 are properly in operation, but liquids are notbeing dispensed from the system, the build-up of excessive pressures isavoided by the relief valves 56, 46.

Although the liquids, under pressure, act upon the respective meters,28, 42, no flow through the meters takes place, since the valve 31, atthe dispensing nozzle, blocks fluid flow through the gasoline system,and the oil system is so designed, as heretofore described, that theoil, even under substantial pressure, is ineffective to overcome thefriction of the meter '42 and associated mechanism. This is anadvantageous feature of the system in that the oil may be maintainedunder considerable pressure, to facilitate the flow of relativelyviscous oils, and to minimize the effect of changes in viscosity due totemperature changes, etc.

To dispense liquids from the system, the lever 33, at the nozzle 39, isoperated to open the valve 31. This permits the gasoline under pressureto flow through the meter 28, and effects the rotation of the metershaft 52 and main shaft 58 in proportion to the volume of gasolinepassing through the meter. Rotation of the main shaft causes or permitsthe oil meter 4-2 to operate, whereby oil under pressure passestherethrough in proportion to the flow of gasoline, as determined by thesetting of the adjusting shaft 71. The oil passing through the systementers the dispensing nozzle through the valve 44 and is mixed anddispensed with the gasoline.

in respect of the flow of liquids through the system, it is to be notedthat the maintenance of the oil under considerable pressure greatlyreduces the mechanical load upon the gasoline meter required to entrainthe oil meter. Thus, the oil meter, once caused or permitted to operate,by operation of the gas meter, is powered largely by the force of theoil under pressure.

During the dispensin of a liquid mixture from the system, the main shaftis caused to rotate at a constant rate relative to the unit volume ofmixture dispensed, regardless of the relative percentages of thecomponent liquids of which the mixture is comprised. Rotation of themain shaft 58 effects the operation of volume and price indicators 77,74, respectively, whichindicators are, as a general rule, reset to zeroprior to each dispensing operation. The volume indicator 77 being drivendirectly from the main shaft 58, indicates the volume of mixturedispensed, regardless of the relative percentages of the componentliquids thereof. The price indicator 74, which is also driven from theshaft 58, is also operated in proportion to the volume of mixturedispensed, but is arranged automatically to reflect the unit price ofthe particular mixture dispensed, regard being had in this latterinstance for the relative proportions and respective unit prices of thecomponent liquids.

It should be understood that the foregoing description is intended to beillustrative only, as certain changes may be made in the specificapparatus disclosed herein without departing from the clear teachings ofthe invention. By way of example and not of limitation, the apparatusand system is not limited to the dispensing of a gasoline-oil mixture,but is equally applicable to the dispensing of various liquid mixtures,including mixtures of two or more different grades of gasoline, in anydesired proportion. Accordingly, reference should be made to theappended claims in determining the full scope of the invention.

Weclaim:

1. In a system. for metering and dispensing a mixture of liquids andincluding a first metering device for a first liquid, a second meteringdevice for a second liquid, variable drive means interconnecting thefirst and second metering devices, selectively operable means foradjusting the variable drive means to vary the proportions of themixture of said first and second liquids, and means associated with saidmetering devices for registering the total price of the mixturedelivered; an improved price registering means comprising input meansoperable in proportion to the volume of mixture metered, transmissionmeans operated by said input means, said transmission means including aplurality of output elements independently adjustable thereto, a priceindicator operable by said output elements, and means including saidselectively operable means for selectively rendering one of said outputelements at a time effective to operate said price indicator, thearrangement being such that the output element rendered effective bysaid selectively operable means reflects the predetermined unit price ofthe liquid mixture selected by operation of said selectively operablemeans, said predetermined unit price being arbitrarily determinableindependently of the proportions of the mixture.

2. The system of claim 1, in which said input means is a shaft rotatablethrough a predetermined angle in response to the delivery of apredetermined quantity of mixture regardless of the proportions thereof.

3. The system of claim 1, in which said transmission means comprises aplurality of gears of graduated sizes rotated in unison by said shaft,and said output elements are selectively engageable with said gears.

4. The system of claim 1, in which said output elements comprise drivegears, said price indicator has an input gear connected to its input,said drive gears are selectively engageable with said input gear, andsaid selectively operable means are operable to move said drive andinput gears into and out of engagement in accordance with theproportions of the liquid mixture determined by the setting of saidselectively operable means.

5. The system of claim 1, in which said input means comprises a shaftrotatable through a predetermined angle in response to the delivery of apredetermined quantity of mixture regardless of the proportions thereof,and the variable drive means interconnecting the first and secondmetering devices comprises first and second sets of'proportioning gearscarried in fixed relation to said shaft, first and second sets oftransmitting gears carried by the respective metering devices, and meansincluding said selectively operable means for operatively engagingselected proportioning and transmitting gears of the re spective sets.

6. The system of claim 5, in which said shaft is rotated by one of saidmetering devices and the other metering device is operated by rotationof said shaft.

7. The system of claim 6, in which the respective sets of proportioningand transmitting gears are so arranged that in all operative conditionsof said selectively operable means the total quantity of liquid passingthrough said first and second metering devices is related in the sameproportion to rotary movement of said shaft.

8. In a system for metering and dispensing a mixture of liquids andincluding a first metering device for a first liquid, a second meteringdevice for a second liquid, drive means interconnecting the first andsecond metering devices, first pressure means to supply said firstliquid under pressure to said first metering device, second pressuremeans to supply said second liquid under pressure to said secondmetering device, and dispensing means for discharging liquids passedthrough said metering devices, the improvement characterized by saidfirst metering device being of a type adapted to be operated in responseto a liquid pressure difierential between the inlet and the outlet sidesthereof, said second metering device being of a type Which isnon-operable in response to a substantial liquid pressure difierentialbetween the inlet and outlet sides thereof, said second pressure meansbeing adapted to efiect the application of substantial liquid pressureat the inlet of said second metering device, and a dispensing valve onthe outlet side of said first metering device for controlling the flowof said first liquid therethrough, the arrangement being such that uponthe opening of said valve said first liquid is caused to flow throughand operate said metering device, the operation of said first meteringdevice thus efi'ected enabling the operation of said second meteringdevice in relation to said first metering device as determined by saiddrive means, said second meter, upon initiation of operation thereof,being driven in part by said second liquid and in part by said drivemeans.

9. The system of claim 8, in which said first pressure means includes avalve normally tending to render the first pressure means ineffectiveand operable in response to the proper operation of said second pressuremeans to render said first pressure means effective.

10. The system of claim 9, in which said first and second pressure meanscomprise first and second pumps, and said valve is a pressure responsivevalve operable in response to a predetermined pressure at the outletside of said second pump to render said first pump effective.

11. The system of claim 8, in which said second pressure means includesa relief valve to limit the pressure under which said second liquid ismaintained.

12. A system for metering and dispensing a mixture of liquids,comprising a first liquid system including first pressure means tomaintain a first liquid under pressure, a second liquid system includingsecond pressure means to maintain a second liquid under pressure, meansto dispense a mixture of said first and second liquids from saidsystems, valve means in one of said liquid systems normally renderingsaid one system inelfective for the delivery of liquid, and valvecontrolling means in the other of said liquid systems operative whensaid other system is conditioned for liquid delivery to actuate saidvalve means to a condition rendering said one system elfective for thedelivery of liquid.

13. In a system for metering and dispensing a mixture of liquids andcomprising a first liquid system including first pressure means tomaintain a first liquid under pressure, a second liquid system includingsecond pressure means to maintain a second liquid under pressure, andmeans to dispense a mixture of said first and second liquids from saidsystems, the improvement which comprises control means operative inresponse to the failure of one of said pressure means to operateproperly to render the other of said pressure means ineffective, saidfirst and second pressure means comprising pumps arranged in tandem, andsaid control means comprising a pressure responsive valve operable inresponse to predetermined pressure created by one of said pumps torender efiective for liquid delivery the system supplied by the other ofsaid pumps.

References Cited in the file of this patent UNITED STATES PATENTS1,964,028 Boynton et a1 June 27, 1934 2,024,115 Schwartz Dec. 10, 19352,743,843 Bliss May 1, 1956 2,829,800 Kirchoif Apr. 8, 1958

